Conventionally, in order to manage a job account system for checking and analyzing a use record for each user and a use log and print log for the prevention of printing of a confidential document, it is necessary to acquire information about jobs executed by a printing apparatus or it peripheral device. As a method of acquiring such job information, the following method is available.
FIG. 11 is a block diagram for explaining a method of managing a print log in a conventional printing system. As shown in FIG. 11, in the printing system constituted by a host computer 1100 and printing apparatus 1110, when the user designates to print, for example, a document from an application 1101 in the host computer 1100, the application 1101 issues a print command to a graphic device interface (GDI) 1102 by using an application programming interface (API) provided by an operating system (OS).
The GDI 1102 converts the print command issued from the application 1101 into a form suitable for target printing equipment (the printing apparatus 1110 in this case), and transmits it to a spooler 1103. Note that a set of print commands will be referred to as a “job”. A print command is described by, for example, a page description language (PDL).
In this case, the spooler 1103 transmits the job from the GDI 1102 to the printing apparatus 1110. With this operation, the printing apparatus 110 properly interprets the job and executes printing.
A print log acquisition unit 1104 then acquires the print log by a GDI hook method or job attribute acquisition method (to be described later).
According to the GDI hook method, the application 1101 hooks the print command issued to the GDI 1102, and counts, for example, the number of paper discharge commands to know the number of printing sheets required for the job. In addition, information about paper size, layout, one-sided/double-sided printing, gathering, and the like can be acquired by hooking proper commands.
The job attribute acquisition method uses the API of an OS. Some OSs provide an API for acquiring information about printing, e.g., the number of pages to be printed and the number of sheets, which is held in the spooler 1103. A print log management unit 1105 monitors the spooler 1103, issues a proper API when a job is input, and acquires information about printing, thereby forming a print log.
The conventional methods, however, have the following drawbacks because information is acquired in the host computer 1100 which inputs a job.
(1) The print log acquisition unit 1104 must be installed in the host computer 1100. That is, an operation environment must be set. This requires much labor.
(2) The print log acquired by the GDI hook method or job attribute acquisition method may differ from the actual print result. For example, a hard return or forced paper discharge may occur on the printing apparatus 1110 side at an unexpected time, resulting in a change in the number of pages, some pages may not be discharged because of jam, or no job may be executed because of power disconnection.